- Notaries1
- Nouel, Jacques, 1551-1
- Novi, Lisa di1
- Numbers (Provenance)1
- Numerical division of sacred works1
- Nuti, Giovanni, 1952-1
- Nāṣir al-Dīn Shāh, Shah of Iran, 1831-18961
- Ochoa family1
- Old age1
- Olive oil industry1
- Order of the Golden Fleece1
- Ordinances, Municipal1
- Oria, Johannes d'1
- Orlandini, Stefano1
- Orta, Garcia de, active 16th century1
- Ortiz family1
- Orto, Giovanni dall'1
- Ospedale degli Innocenti (Florence, Italy)1
- Otto I, Holy Roman Emperor, 912-9731
- Ovando, Nicolás de, approximately 1460-15111